When a person falls from a vessel or otherwise finds him/herself unavoidably in the sea or other areas of open water, they are referred to as a “casualty”. This is due to the fact that exposure to such conditions can quickly cause numerous physical consequences that eventually may lead to the death of the person. Survival limits can sometimes be measured in minutes. The odds of survival are increased dramatically by the wearing of a buoyant safety harness and means to assist in the rapid location of the casualty.
For example, WO2010/004318 discloses a system for increasing the visibility of a casualty in the water, by deployment of a visible inflatable portion which is constructed such that an open configuration is maintained after deployment. The device “rides the waves” and continues to be visible even in rough water. The “streamer” devices disclosed in U.S. Pat. No. 5,421,287 and JP07304492 aim to achieve a similar effect, by means of “streamer” elements which can be packaged for easy wear by a user and caused to unfurl if the user finds themselves in water. US2005/0221700 discloses an inflatable bladder which can be tethered to a person or apparatus via a line, the bladder and line being packaged together in such a way that, if the person or apparatus is submerged, the bladder and line are released. The bladder inflates as a ring structure and floats to the surface. Similarly, U.S. Pat. No. 4,004,310 and FR757510 disclose systems of packaging a line within a marker buoy such that, if a user or object is submerged, the buoy can be released and float to the surface, remaining attached to the user or object via the line which pays out freely from within the buoy.
Even with such buoyancy and visualisation aids, time is usually incredibly valuable for the survival of the person. The extreme difficulties encountered in manoeuvring the vessel, securing the casualty and bringing them back aboard are often insurmountable. Any delay waiting for assistance from the Coastguard and other rescue services results, even when recovering the person alive, in their subsequent death despite the best medical care available. This is of particular concern for crews in waters which may be hundreds or even thousands of miles from land.
It must be understood that the handling characteristics of a vessel changes as speed changes in any given condition. The worse the conditions, the more profoundly the characteristics change. Therefore, sailing yachts in rough seas can be stable at speed when 90° to the wind with precise helm control available. However, they become very unstable and almost impossible to steer when pointing to wind at less than 1 knot in the same seas. Also, orientated at an angle close to the wind direction usually results in the waves arriving from a similar direction. This tends to excite the pitching action which can become very violent, especially if the waves match the natural frequency of the vessel. During this phase, the rig of a yacht becomes a serious hazard if control lines begin to flog or the boom sweeps above the deck unexpectedly. Rigging lines can become tangled then tensioned inappropriately leading to loss of control. As speed approaches zero, steerage is completely lost and the force of wind on the hull and superstructure, combined with the action of the waves, dictate the location and movement of the vessel. Similar is true for power driven vessels. All vessels with zero forward motion rotate so their bows point substantially downwind and they drift in a downwind direction. It is possible to counteract this to a greater or lesser extent with a power driven vessel but sailing vessels are particularly badly affected. These effects can render the time window when the casualty is in close range during a recovery attempt very short indeed, making further recovery attempts necessary. Small craft can be so unstable that it can be hazardous to conduct slow speed manoeuvres in rough seas. Therefore, few sailors ever practice or attempt precise manoeuvring at slow speed in rough weather.
Various National and International marine organisations suggest assorted manoeuvres for rapidly returning the vessel to the location of the casualty and recommend that such manoeuvres are practiced regularly. Typically, such practice is conducted in fair weather with the casualty simulated by a flotation device (often a fender) attached to a drag device (often a bucket) by means of a short length of rope. Such a rope is relatively easy to pick up by a sweeping action with a boat hook below the surface of the water aiming between the flotation device and the drag device.
Even with such an easily secured object as above, poor sea conditions can make attaching the boat hook difficult, necessitating many attempts. The combined effect of the motions in even modest seas can result in rapidly changing vertical distance between the object to be picked up and the vessel from which the person attempting the pickup is deploying the boat hook. Due to the necessity to have the maximum time available in contact with the object to carry out this task, it is usual to first attempt the pickup from the fore part of the vessel where the pitching motion is amplified by the distance from the centre axis of buoyancy. This is particularly so in a motor driven vessel where the recovery must be towards the bow to avoid the possibility of the casualty contacting the propeller situated aft. In all cases, if this fails, the rescuer moves further aft if sufficiently close to the casualty for a second attempt.
Almost universally, the adopted ‘best practice’ involves the vessel manoeuvring to a position placing it upwind of the casualty, the rationale being that it allows the vessel to be in close proximity to the casualty for the longest period of time before natural forces can separate the parties. During this brief period, the crew must try to firmly hold the casualty. In the case of a yacht, this usually means lying on the deck and reaching down beneath the guard rails into the water. On a pitching yacht in a rolling sea, when water is coming over the deck, this may lead to the rescuer contacting the casualty and then having to hold them as their full weight (often 100-150 kgs for a person in soaked clothing) is transferred as the yacht rises, whilst the wave supporting the casualty falls. This places the rescuer in jeopardy of being pulled overboard and, in many cases, leads to the casualty being released due to excessive loading. Unfortunately, this manoeuvre also places the casualty below the curved hull of the vessel as the hull rises and falls. Apart from the consequences of an impact with the hull, it also can push the casualty underwater further straining the hold any crew may have and/or cause them to be lost to sight as the vessel moves on.
Unhappily, a casualty wearing a fully inflated lifejacket may have some advantages in terms of survival but is very restricted in their ability to assist in their own recovery. This is because the pontoons of the jacket form an unfamiliar and formidable barrier to arm movements towards the front of the body, above the waterline or above the head.
Some methods recommend using the swim platform or ladder at the stern of the vessel. However, in rough seas, the ladder becomes extremely dangerous and the stern has all the characteristics of an extremely large hammer.
The recovery situation of a real casualty, as opposed to the simulation used in exercises, is far worse. A marine safety harness is manufactured from webbing that lies flat conforming to the casualty's body shape. Some are provided with a lifting Becket consisting of a webbing loop which is stored flat, offering almost no opportunity for entry of a boat hook and sometimes needs the active intervention the casualty to deploy. The other obvious lifting point is the D ring used to attach the harness line. This is typically around 2 inches in diameter, offering a very small target which may be flat against the body and will be submerged and concealed beneath the supporting pontoons of the lifejacket.
This is clearly illustrated by a report to Solent Coastguard on 20 Jun. 2014 where the crew of a yacht failed, after several attempts, to recover a rescue dummy in sheltered water at the mouth of the River Hamble in excellent weather and sea conditions.
A conscious casualty may be able to grab a boat hook and assist in attaching a line. In addition to being conscious, the casualty would need sufficient mental faculties and manual dexterity. Cold water will rapidly reduce cognitive abilities, manual dexterity and strength as was highlighted by the UK's Marine Accident Investigation Branch (MAIB) in the case of the vessel Vidar: “Many fishermen erroneously believe that a person falling overboard can help themselves in some way once a rope is thrown to them or a ladder is lowered. However, MAIB investigations have identified numerous accidents where fit and healthy persons who have fallen overboard have lost all ability to help themselves within a minute or two due to the debilitating effects of cold water shock and ingestion of water.” (MAIB Very Serious Marine Casualty Report no. 19/2013, August 2013)
An alternative method of rescue involves the use of a device called a Lifesling® or Seattle Sling which can be effective with conscious casualties who retain sufficient manual dexterity to don it following contact. The equipment is most effective if the casualty is able to catch the line or the vessel is manoeuvred around the location of the casualty until they are in contact with the line and then able to pull the sling into position. Unfortunately, in any rough sea, a casualty may be unlikely to be able to see the line as it comes into contact with them and may not be able to distinguish the difference in feel between water sloshing over their face and the fall of a line. Furthermore, the skill level of the rescuers must be relatively high to allow them to manoeuvre in an arc around the casualty yet ensure they avoid simple mistakes such as allowing the lifting line to become tangled in the propeller. However, this equipment is frequently carried as standard equipment on many vessels but, to lift the casualty requires that a block and tackle is available, something that is rarely found on most modern yachts.
Another method of bringing a casualty back aboard is by means of a Jason's Cradle® or similar. This is a form of netting that is rarely successful in rough seas due to the alternating buoyancy of the netting. In addition, it may require multiple rescuers working in close coordination to properly operate unless substantial deployment machinery is already installed on the vessel.
Many other devices involve throwing lines and dropping equipment into the water for the casualty to find and deploy. They all offer some benefits however, they also provide multiple tangle and hindrance opportunities in the rescue area if not used and usually require considerable input from a conscious casualty who retains manual dexterity. US2004/0023574 describes a throw bag which may be worn on the body of a person, containing a line the end of which is attached to the person at a different point. If they are able to, they may release the throw bag from its location when worn whilst leaving the end of the line attached to them, open the lid to free the remainder of the line and throw the bag towards a rescuer. It is easy to see how such a manoeuvre might be difficult for a casualty who has fallen overboard in high seas, wearing an inflated life jacket.
Therefore, there is a need for an effective, simple, low cost device that is intuitive in use and makes use of the standard vessel equipment and systems without adding further dangers when used, for example caused by loose floating lines in the water, allows the vessel to be under full control for as long as possible during the contact phase and not require positioning that places the casualty or rescuers in jeopardy. Furthermore, the operational skill level requirement must be low to allow for both the confusion caused during the extremely stressful situation of a genuine MOB and minimum skill levels that may be available. The device should be available to be manufactured with a new harness, equipment or clothing or retrofitted to existing harnesses and other related equipment.